The Colonization of Carbapenem-Resistant Klebsiella pneumoniae: Epidemiology, Resistance Mechanisms, and Risk Factors in Patients Admitted to Intensive Care Units in China

Abstract

Background Carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a threat to public health, most notably as a superbug causing nosocomial infections. Patients in the intensive care unit (ICU) are at increased risk of hospital-acquired K pneumoniae infection, especially CRKP. This study was conducted to investigate the frequency of gastrointestinal and nasopharyngeal K pneumoniae colonization and its contribution to infections in ICU patients. Methods A 3-month prospective cohort study was performed in which 243 ICU patients were screened for intestinal and nasopharyngeal carriage of K pneumoniae at admission and once per week thereafter. The colonization and clinical infection isolates were analyzed by antimicrobial susceptibility testing to identify CRKP and were characterized by multilocus sequence typing (MLST) and whole-genome sequencing combined with epidemiological data to investigate the resistance mechanisms and assess the possible transmitted infection. Results Twenty-eight percent (68 of 243) of patients tested positive for carriage of K pneumoniae immediately upon admission to ICU, 54% (37 of 68) of which were nonduplicate CRKP isolates. Patients with carbapenem-susceptible K pneumoniae (CSKP) colonization at admission were more likely to acquire CRKP colonization during the ICU stay compared with patients without K pneumoniae colonization at admission. The incidence of subsequent CRKP infection in the baseline CSKP (32.3%, 10 of 31) and CRKP (45.9%, 17 of 37) carrier group was significantly higher than that of the baseline non-KP carrier group (8.6%, 15 of 175). The risk factors associated with acquired CRKP colonization during the ICU stay among negative CRKP colonization at admission included previous exposure to carbapenem, tigecycline or β-lactam/β-lactamases inhibitor, and invasive processes or surgical operations. Sixty-four percent (27 of 42) of patients with K pneumoniae infection were colonized by clonally related K pneumoniae strains according to enterobacterial repetitive intergenic consensus sequence-polymerase chain reaction analysis. ST11 (72%, 53 of 74) was the most predominant MLST type of clonally related CRKP isolate colonizing these patients, followed by ST15 (26%, 19 of 74). Conclusions The colonization of K pneumoniae may increase the incidence of corresponding K pneumoniae infection in critically ill patients in the ICU. High prevalence of ST11 CRKP (due to blaKPC-2) carriage and infection in ICU was observed.

Characterization of Carbapenem-Resistant Klebsiella pneumoniae ST15 Clone Coproducing KPC-2, CTX-M-15 and SHV-28 Spread in an Intensive Care Unit of a Tertiary Hospital

“…Most of the patients with CRKP infection in this study had an advanced age, long hospital stays, a history of antibiotic treatment and invasive operations or treatments during hospitalization, which have been confirmed as important risk factors for CRKP colonization. 29,30 It was reported that CRKP colonization can increase the risk of subsequent infection. 31 Also, the relatively weak immune function of ICU patients may enhance the invasive ability of pathogens, which can be seen in three patients with bloodstream infection.…”

Colonization Dynamics of Multidrug-Resistant Klebsiella pneumoniae Are Dictated by Microbiota-Cluster Group Behavior over Individual Antibiotic Susceptibility: A Metataxonomic Analysis

“…Numerous recent publications have reported that healthy hosts may be asymptomatically colonized with ESBL-producers, with an overall colonization rate of 14%, which is more than a 5% increase from previous studies; there are important geographical differences in the prevalence. In Asia and Africa, the colonization rate may be as high as 46%, whereas in Europe and the Americas, the colonization rate is lower (3-6% and 2%, respectively), but still significant, with a CTX-M-type ESBL dominance [19,20]. The rate of colonization with carbapenemase-producing Enterobacterales is usually much lower (<10%).…”

“…The rate of colonization with carbapenemase-producing Enterobacterales is usually much lower (<10%). Unfortunately, it is also increasing worldwide, with some hotspots, for example, in China, with rates as high as 54% [20]. The import and spread of ESBL-or carbapenemase-producers has been recognized as a serious concern, and the travel to (sub)tropical regions (where colonization rates are known to be high) is a risk factor for acquiring colonization by the abovementioned resistant strains [19,21,22].…”

Rising Klebsiella pneumoniae Infections and Its Expanding Drug Resistance in the Intensive Care Unit of a Tertiary Healthcare Hospital, Saudi Arabia

“…Carbapenem-resistant K. pneumoniae is emerging as a risk to public health as it causes various nosocomial infections, notably respiratory tract infections. Patients in the ICU are at a bigger risk of hospital-acquired K. pneumoniae infection, particularly infections caused by carbapenem-resistant K. pneumoniae [ 13 ]. Carbapenems, a β-lactam antibiotic, target cells by inhibiting transpeptidases which prevent the synthesis of peptidoglycan, a necessary structural component, leading to cell lysis.…”